One proposed structure of an engine misfire detection apparatus detects a misfire of an engine mounted on a vehicle, based on an output torque command value of a first motor generator (see, for example, Japanese Patent Document 1). This vehicle is equipped with the engine, a planetary gear mechanism that has a carrier connected to a crankshaft of the engine and a ring gear connected to an axle of the vehicle, the first motor generator that is connected to a sun gear of the planetary gear mechanism, and a second motor generator that is connected to the axle. The engine misfire detection apparatus of this proposed structure varies the output torque of the first motor generator in synchronism with an explosive combustion timing of the engine, in order to reduce a potential vibration caused by torque pulsation of the engine. An engine misfire is detected in response to a significant fall of the output torque command value from its previous value.
Patent Document 1: Japanese Patent Laid-Open No. 2000-240501